DESCRIPTION: (adapted from abstract) The Harvard School of Public Health's Perinatal HIV Prevention Trial, Thailand study (PHPT) and Thailand's recently established National Data Center for AIDS Vaccine Development (NDCAVD) at Mahidol University's Institute for Population and Social Research have combined efforts to strengthen Thailand's research capacity in the areas of data management and statistics within the context of clinical trials. The specific aims of this proposal are to investigate the epidemiology of four viral infections -- Hepatitis B (HBV), Hepatitis C (HCV), Cytomegalovirus (CMV), and Human Herpes Virus-8 (HHV-8) -- in relation to HIV among a large representative sample of pregnant Thai women. These viruses were chosen for their public health importance or their theoretical/known associations with HIV. This study plans to: 1) determine the seroprevalence of each infection and associated risk factors in HIV+ and HIV- pregnant women; 2) determine the rates of transmission of these viruses and risk factors for transmission in HIV+ women who are not breast feeding; 3) explore the relationship of perinatal HIV transmission to these other viruses; and 4) determine whether co-infection by these viruses are prognostic risk factors for progression of HIV disease in mothers and children. The sera from 35,000 women screened for HIV within the PHPT are available for testing. All HIV-positive women, as well as a randomly selected group of HIV-negative (stratified by urban/rural residence and age), will be screened for these four viruses. All infants born to co-infected (HIV and another virus) mothers will also be tested for the corresponding virus. Sociodemographic and behavioral data from all women, the HIV status of the infants and progression data from HIV-infected children are available from the PHPT. NDCAVD will perform all necessary data management and collaborate in the analysis and interpretation. As a retrospective substudy, this project will provide appropriate training for NDCAVD researchers in the data management of clinical trials, as well as answer some important questions regarding the association of these viruses with HIV and perinatal transmission.